Association Between COVID-19 Vaccine Doses and Neurosensory Symptoms Among COVID-19-Positive Patients: A Retrospective Cross-Sectional Study.

Authors

Jaime Ricardo Sevillano Giraldez, Grace Thompson, Luis Escobar, Isaac Fernández Carmago, Luis Alberto Flores

Published in

Cureus. Volume 18. Issue 9. Pages e116226. Epub Sep 14, 2026.

Abstract

Ageusia and anosmia are common manifestations of COVID-19. This study examined whether their frequency among infected patients was associated with the recorded number of Pfizer-BioNTech vaccine doses; it was not designed to estimate causality or vaccine effectiveness.
We conducted a retrospective cross-sectional analysis of 5,348 COVID-19-positive patients over five years of age followed by the San Miguelito Health Region, Panama, from July 7, 2021, through November 2, 2022. Unvaccinated patients and vaccinated patients whose recorded doses were exclusively Pfizer-BioNTech were included. Separate logistic regression models estimated associations between vaccine dose category (zero, one, two, or three to four doses) and self-reported ageusia and anosmia, with two doses as the reference. A post hoc sensitivity analysis additionally adjusted for swab month.
Ageusia was reported by 507 patients (9.48%), and anosmia by 584 patients (10.92%). In the primary adjusted models, compared with two doses, adjusted odds ratios (aORs) for zero, one, and three to four doses were 1.87 (95% confidence interval (CI) 1.48-2.38), 2.68 (95% CI 1.99-3.60), and 0.26 (95% CI 0.18-0.36), respectively, for ageusia, and 1.82 (95% CI 1.46-2.27), 2.53 (95% CI 1.91-3.35), and 0.18 (95% CI 0.12-0.25), respectively, for anosmia. After categorical adjustment for swab month, all six dose-category estimates were attenuated, and none remained statistically significant.
Primary models identified strong associations between recorded vaccine dose category and self-reported ageusia and anosmia among infected patients, but these associations did not persist after adjustment for swab month. The results are compatible with substantial confounding by epidemic period and should not be interpreted as causal effects or estimates of vaccine effectiveness.

PMID:
42877857
Bibliographic data and abstract were imported from PubMed on 16 Oct 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.